A180842 Number of nX4 arrays containing 4 indistinguishable copies of 1..n with lexicographical ordering of rows strictly increasing and columns strictly decreasing

1, 0, 44, 14284, 8554238, 9893281255, 19903018463755

Offset

1,3

Comments

Column 4 of A180843

Links

Table of n, a(n) for n=1..7.

Example

Some solutions for 3X4
..2..1..1..1....2..1..1..1....2..1..1..1....2..1..1..1....2..1..1..1
..2..3..2..1....2..3..2..1....2..3..2..1....2..3..2..1....2..3..3..1
..2..3..3..3....3..2..3..3....3..3..3..2....3..3..2..3....3..3..2..2
...
..2..1..1..1....2..1..1..1....2..1..1..1....2..1..1..1....2..2..1..1
..2..3..2..2....2..3..3..2....2..3..3..2....2..3..3..2....2..2..3..1
..3..3..3..1....3..2..1..3....3..3..1..2....3..3..2..1....3..1..3..3
...
..2..2..1..1....2..1..1..1....2..1..1..1....2..2..1..1....2..2..1..1
..2..2..3..3....3..2..2..1....3..3..2..1....3..1..2..1....3..1..2..1
..3..1..3..1....3..3..2..3....3..3..2..2....3..2..3..3....3..3..3..2

Crossrefs

Sequence in context: A266853 A323315 A007105 * A172753 A268425 A183749

Adjacent sequences: A180839 A180840 A180841 * A180843 A180844 A180845

Keyword

nonn

Author

R. H. Hardin Sep 20 2010

Status

approved